1. Field of the Invention
The invention relates to a device for the generation of compressed air comprising a compressor which supplies air to a user via a pressure line and where a pressure controller is furnished in the pressure line.
2. Brief Description of the Background of the Invention Including Prior Art
Such a device is known from the European Patent Application EP-B1-0,051,760. According to this reference, a pressure controller is employed for the interruption of the supply of air to a user if a predetermined pressure has been reached on the user side. The pressure controller blocks the supply stream from the compressor versus the user and diverts the supply stream into the atmosphere. In addition to a pressure control by way of the pressure controller, the compressor is in this case switched off by disengaging the compressor from its drive by uncoupling of a coupling.
It also known to employ either the pressure controller of the recited kind or to effect the interruption of the supply by stopping the compressor. The two possibilities of the supply interruption can be employed simultaneously, as is the case in the conventional construction. This is associated with the advantage that energy is saved during a stopping of the compressor, and that, upon renewed turning on of the compressor, the compressor has to overcome only a small starting torque when starting a feeding of air into the supply line vented by the pressure controller.
However, the stopping of the compressor in the non-supply phase is associated with the disadvantage that in particular the line section from the compressor to the pressure controller is subjected to substantial temperature variations. Based on these temperature variations, there can occur an undesirably high concentration of condensed water in the recited line section and in following labyrinth of the pressure controller. The recited region of the device tends consequently to icing, in particular in case of low ambient temperatures. This in turn has the result that, in case of a renewed requirement of compressed air, the compressor can only feed toward a pressure side blocked by icing.